Experimental Research On Performance Of Crumb Rubber And SBS Compound Modified Asphalt Mixture Under Freeze-Thaw Cycles And Dry-Wet Cycles With Salt Action

The winter snow in seasonal frozen area is frequently,and this phenomenon affects the normal operation of transportation.Deicing salt is a method of deicing or snow-melting that widely used at present.But this method will make the asphalt pavement under the action of freeze-thaw cycles and dry-wet cycles with snow-melting salt,it is easy to cause diseases of asphalt pavement.Therefore,it is of great significance to study the performance degradation of asphalt pavement under the action of freeze-thaw cycles and dry-wet cycles with snow-melting salt.(1)In this article,I adopt the crumb rubber and SBS compound modified asphalt mixture as the test subject.Firstly,the natural factors and human factors that affect the performance of asphalt mixture are discussed.Secondly,the principle of melting ice melt snow and the erosion mechanism of melt salt for asphalt mixture are analyzed.Thirdly,the degradation mechanism of asphalt pavement under various factors is analyzed.(2)With the method of indoor test,by deicing salt solution of different concentrations and different number of freeze-thaw cycles and the dry-wet circulation mechanism to accelerate the simulation seasonal frozen area the bad conditions of use of crumb rubber and SBS compound modified asphalt mixture specimen for processing.Salt solution concentrations are 0%(basic),4%,8%,12% and 16%.The freeze-thaw cycles and the dry-wet circles are 0 times(basic),5 times,10 times and 15 times.The tested samples were tested respectively by rutting test,low-temperature bending test and freeze-thaw split test.The main conclusions in this paper are as follows:(1)When the concentration of deicing salt solution was fixed,with the increase of freeze-thaw and the dry-wet cycles,the dynamic stability,the maximum bending strain and tensile strength ratio of crumb rubber and SBS compound modified asphalt mixture with ratio are declining,the influence to the performance by the number of times of freeze-thaw cycles and the dry-wet circulation in turn is 15 times > 10 times> 5 times;(2)When the freeze-thaw cycles and the dry-wet cycles times are fixed,the dynamic stability,the maximum bending strain and tensile strength ratio of crumb rubber and SBS compound modified asphalt mixture with deicing salt concentration were slowly rising at first,when the concentration of deicing salt reached about 8%,the tendency began to slow down,therefore,it will make less influence on the properties of materials when the concentration of deicing salt was 8%;(3)The influence of freeze-thaw cycles and dry-wet cycles on the crumb rubber and SBS compound modified asphalt mixture is higher than that of deicing salt erosion.